Abstract: Plant for filtering substances to be cleaned of various kinds of semi-solid or liquid polluting substances, constituted by filtering devices (5) connected to each other, including a first circulation circuit of the substances to be cleaned introduced into each filtering device (5) for discharging the polluting substances after having been cleaned; a second circulation circuit of the cleaned liquids and the exit from the plant, and the possible collection into suitable containers; a third circulation circuit of suitable plant washing liquids, so as to clean the various plant component parts of the polluting substances remaining after one or more working cycles. The plant being arranged to set pre-established operative programs, such as to determine a working cycle composed by a first rest step, a second filling step, a third filtering step, a fourth emptying step, a fifth discharge step, a sixth rinsing step and a seventh washing step.